Google relies on user proximity to provide local results for keywords. How strong is the proximity factor? How fast does the ranking decrease by distance from the location of a business?
The goals of the study are to try to estimate the drop in the ranking by geographical distance and to measure the variability due to the local context (city).
For this study, we focused on personal injury lawyers in major US cities. We collected 20 top-ranking personal injury lawyers in each of the 10 largest cities.
For each of these law firms, we used the service Local Falcon to collect Google My Business rankings for listings that show up either in the Maps portion of the organic search or from a search in the Google Maps Local Finder (i.e. Google Maps).
We collected their rankings for the keyword car accident lawyer at 225 locations on a 15x15 grid centered on their geographic location.
This is an example for the city of Miami:
At the location of the law firm, it ranks 1st for the keyword car accident lawyer. Its ranking drops, however, as soon we are further away from its location. At the fringe of the grid, the law firm does not appear anymore in the top 20 (its exact ranking is not tracked anymore by Local Falcon).
This drop in the ranking can vary drastically between law firms, even in the same city. We see this variation if we flank our initial example with 2 other samples from Miami:
On the left, we see a very quick drop in the ranking. On the right, we see the case of a law firm which ranking does not drop much. The grid is always centered on the location of the target law firm.
To account for this high variation between the firm, we need to collect several samples in each city: 20. For 10 law firms, we used a radius of 5 miles, a finer granularity to better highlight the drop in ranking around the exact location of the firm. For 10 other law firms, we used a radius of 10 miles, to better identify the distance where most of the firms drop out of the top 20.
Most of the 200 law firms rank 1st at their own location (58%).
From the latitude and longitude of each of the 225 measurements on the 15x15 grid, we compute the geographical distance to the location of the target law firm. We then average the ranking of a law firm by mile distance to its own location.
For instance, with our previous example in Miami, we see that the law firm ranked first at its own location (distance = 0 miles). The ranking drops quickly, and the average position of all the measurements taken between 0 and 1 miles average to ~9. The average rank stabilizes then around 18 as from the third mile already. Please note that we made the following choice: Local Falcon does not collect rankings above 20, they are just collected as “20+”. In order to compute the average rankings, we impute these “20+” values to the value 21. This has an impact on the computation of the average ranking.
To obtain more stable measurements of the drop in ranking, we average the rankings from each law firm.
We start by visualizing the average rank at each mile from the center location for each law firm in each city. The average rank across all law firms is shown in pink. It is computed with a rank of 21 for the firms out of the top 20 and for which the rank is not recorded anymore by Local Falcon.
We observe that the drop in ranking varies greatly between law firms. Some firms do only see a small drop in their ranking, even at 5 or 10 miles from their location.